Inorganic acid esters of didihydroxypropylamines



Patented Jan. 21, 1941 UNITED STATES PATENT OFF-ICE INORGANIC ACID ESTERS OF DIDIHY- DROXYPROPYLAMIN ES Anderson W. Ralston and James Harwood, Chicage, 11]., assignors to Armour and Company, Chicago, 11]., a corporation of Illinois No Drawing.

7 Claims.

wherein R is a straight chain hydrocarbon group containing at least twelve carbon atoms.

Compounds which contain a long hydrocarbon chain attached to hydrophylic groups or hydrocarbon radicals containing hydrophylic groups are of interest as wetting agents or detergents. These compounds function essentially by reason of their effect upon surface tension. A large number of wetting agents have been proposed in the past few years, and some few of these can be classed as detergents. The most common detergents are, of course, the sodium salts of the fatty acids' and these soaps have been and will continue to be used in large amounts for cleaning purposes. However, the soaps possess some disadvantages and recently several synthetic detergents have been proposed which are free from these objectionable characteristics. One of the objections to most soaps is that in water containing calcium ions an insoluble calcium soap is formed which forms a scum upon fabrics. The sudsing and detergent properties of soaps are markedly reduced in hard water and one of the main purposes in preparing other detergents is to obtain compounds which are satisfactory under these conditions. It is also quite desirable to develop detergents which function over a wide pH range so that they can be used under both alkaline and acid conditions. These newer detergents are more costly to prepare but in many instances they are preferred.

We have set ourselves to the problem of preparing wetting agents which have superior de- Application January 30, 1940, Serial No. 316,450

tergent properties. During this work we have synthesized a large number of compounds and have evaluated them as detergents. In the course of our work we have prepared a new series of compounds which can be broadly designated as substituted didihydroxypropylamines and we have found that the esters and their alkali metal salts thereof possess superior detergent powers over a wide pH range and under conditions, unfavorable to the use of the older types of detergents, such as soaps. The compounds of our invention are inorganic esters, such as the phosphoric acid or sulfuric acid esters (and salts thereof) of amines having the structural formula.

wherein R is a straight chain hydrocarbon radical containing at least twelve carbon atoms. Examples of such compounds are the sodium salt of the tetrasulfuric ester of di-(B, v-di'hydroxypropyl) dodecyl amine, the disulfuric ester of di- (/3, 'y-dlhydroxypropyl) octadecyl amine, the monophosphoric ester of di-(B, -dihydroxypropyl) tetradecylamine, the sodium salt of the diphosphoric ester of di-(p, v-dihydroxypropyl) dodecylamine, the tetrasulfuri'c ester of di-(B. v-dihydroxypropyl) octadecenylamine and the potassium salt of the trisulfuric ester of (ii-([3, 'y-dihydroxypropyl) pentadecylam'ine.

All of these compounds are extremely watersoluble and they possess the property of modifying the surface tension of liquids. Their aqueous solutions possess excellent detergent properties.

These compounds can be prepared by esterifying the reaction products of amines and chlorohydrins with sulfuric or phosphoric acid. The di-(B, -dihydroxypropyl) amines are prepared by reacting one mol. proportion of a high molecular weight amine containing at least twelve carbon atoms with two mol. proportions of glycerol monochlorhydrin. The products are then esterified with concentrated sulfuric or phosphoric acid in such a manner that esters are formed.

The general equation for the preparation of the tetrasulfuric esters is as follows:

II HH These compounds can be generally classed as inorganic esters of (ii-(p, 'y-dihydroxypropyl) amines. Both the esters and their salts possess excellent detergent properties in water solutions.

The following examples of the preparation and properties of these compounds can be given:

EXAMPLE 1 Tetrasulfuric esters of di- (5, -dihydromypropyl) dodecylamine One hundred grams of dodecylamine is suspended in 240 cc. of sodium hydroxide solution and 192 grams of glycerine monochlorhydrin added slowly. The addition of glycerine The tetrasulfuric acid ester is prepared by treating. the product with concentrated sulfuric acid. The temperature of the esterincation should not be allowed to exceed 80 C. The sodium salt is obtained by neutralization and the tetrasuliuric ester obtained by exact neutralization of the salt. i

Exams: 2

Two hundred and seventy grams of octadecylamine are suspended in 240 cc. of a 10% sodium hydroxide solution and two hundred and twenty-one grams of glycerine monochlorohydrin added slowly. After the temperature ceases to rise the reaction mixture is heated for two hours at 90 C. The product is then extracted with benzene and the benzene removed by distillatlon. The product is then esterifled with 200 grams of concentrated sulfuric acid. Neutralization of the ester produces the sodium salt from which the free ester can be obtained by acidification.

The above examples illustrate the general method of preparation and the properties of the esters of di- (3, 'y-dihydroxypropyl) amines. It is, of course, possible to prepare these esters starting with mixtures of primary amines. Thus, if we react glycerine monochlorhydrin with a mixture of hexadecylamine and octadecyiamine we prepare compounds some of which will contain an alkyl group having sixteen carbon atoms and the others will have alkyl groups which contain eighteen carbon atoms. We can, of course, also use unsaturated amines such as octadecenylamine and in these cases the alkyl groupwill be unsaturated.

As stated above, the inorganic esters of di- (,8, 'y-dihydroxypropyl) amines possess marked detergent properties in solution. These sulfuric esters can be prepared easily and cheaply by esteriflcation of one or more of the hydroxyl groups with sulfuric acid. These esters and their sodium salts are excellent detergents in water solution and we have found them to be superior to the synthetic detergents now available. The phosphoric acid esters and their salts can be prepared in a similar manner by reacting the di- (dihydroxypropyl) amine with phosphoric acid and forming salts therefrom.

Any primary amine having twelve or more carbon atoms can be used, as well as the corresponding unsaturated primary amine.

Having thus described our invention, what we claim is:

1. Inorganic acid esters and salts thereof a didihydroxypropylamine of the general formula wherein R is a straight chain hydrocarbon radical containing at least twelve carbon atoms.

2. Inorganic acid esters of the class consisting of sulfuric acid and phosphoric acid esters, and

salts thereof, of a didihydroxypropylamine having the formula H H-JJ-OH n- -on H n- H H-c-'--1 -I-R t wherein R. is a straight chain hydrocarbon radi- 15 cal containing at least twelve carbon atoms.

3. The sodium salt of the disulturic acid ester of di-firy-dihydrcxypropyl dodecylamine.

4. The sodium salt of the tetrasulfuric acid ester of di-p,' -dihydroxypropyl) dodecylamine. 0 5. The esters as in claim 2 wherein R is dodecyl.

6. Sodium salts oi inorganic acid esters of the class consisting of sulfuric and phosphoric acid esters or a didihydroxypropyiamine having the formula n-c-on H- -on H 11- -H 11- ---l IR n- -on H-o-OH wherein R is a straight chain hydrocarbon radical containing at least twelve carbon atoms.

7. The esters as in claim 6 wherein R is dodecyl.

ANDERSON W. RALSTON. JAMES HARWOOD. 

